Savannah was my first thought. Then Abigail and Charlotte, then Dakota -- nms at all, but fits quite well. Might be a more recognizable place name as kid's name than Montana (though I know a girl named Montana who is in her early twenties. She goes by Tana exclusively).

I think a fresher all-american girl one might be Lilah/Lila. I love this name and it has (IMO) the best part of Delilah without the connotations.

I love the suggestion of Susannah. It does not get more American than JamesTaylor's version of Oh Susannah (if you were thinking of this as a goofy song, listen to his take on it. It is the perfect ready made lullaby.)